In that night did God appear to Solomon, and said to him, Ask what I shall give you. — 2 Chronicles 1:7
If you will ask anything in my name, I will do it. — John 14:14

Author
Charles Spurgeon
Summary: We can come freely to God because his promise encompasses needs both great and small. Asking in Jesus’ name encourages us and honors him: when other reasons for confidence grow dim, his name retains all its power. But this privilege also places a limit on our prayers. We must not invoke his name for selfish or capricious desires, but for what Christ himself would ask in our place. Our love for him keeps us from putting his name to anything he would not endorse. If Jesus approves our request, we can bring it to the Father with complete confidence.
What a sweeping promise! Anything! Whether great or small, all my needs are covered by that word “anything.” Come, my soul, freely before the mercy seat, and hear your Lord as He says to you, “Open your mouth wide, and I will fill it.”
What a wise promise! We must always ask in the name of Jesus. This encourages us even as it honors Him. This is an argument that never fails. At times every other argument is obscured, especially those we might draw from our own relationship with God or our experience of His grace; but at such moments, the name of Jesus is as powerful at the throne as ever, and we may plead it with complete confidence.
What an instructive prayer! I could ask for nothing to which Christ could not put His hand and His seal. I would not dare use my Lord’s name for a selfish or capricious request. I can use my Lord’s name only for prayers that He Himself would offer if He were in my place. It is a great privilege that we are authorized to ask in the name of Jesus as though Jesus Himself were asking; but our love for Him would never allow us to invoke that name where He would not use it.
Am I asking for what Jesus approves? Would I dare put His seal on my prayer? Then I already have what I seek from the Father.
Source: Faith’s Checkbook. Translation by Allan Roman.
http://www.spurgeon.com.mx/chequera/meditames/noviembre.pdf